New News Biology #62

Antibiotic Resistance

Antibiotics are drugs that can kill bacteria. But over time, these bacteria aren’t killed by the drug anymore, and continue to colonize and multiply.

So how does this process happen?

Imagine you have this colony of bacteria that is causing you a sore throat and headache. You go to the doctor and they prescribe you some antibiotics.

The objective here is that hopefully, after consuming the antibiotics, they come into contact with the colony of bacteria and destroys them.

However, bacteria can develop random mutations in their DNA which may change some characteristics. Occasionally, the bacteria becomes less affected by the antibiotic, and this means that the antibiotic is effectively useless against this new mutated bacteria.

Although the antibiotics go on to kill most of the bacteria within the colony, some of them which have randomly developed a helpful mutation will survive. And because bacteria can replicate so quickly, the resistant bacteria can replicate and form an entire new colony of its own, and they all have the gene for antibiotic resistance. We call this new colony an antibiotic-resistant strain.

Now the problem isn’t with you; its with this new antibiotic resistant strain of the bacteria. It can go on to infect other people, and they may go to the doctor and be prescribed the original antibiotic that you had. But because this strain is resistant, the antibiotic won’t work, and that individual has to go back and get prescribed another different antibiotic.

Occasionally, the already antibiotic-resistant strain will mutate and develop resistance to this new prescribed antibiotic. This means that the new colony is now resistant to two types of antibiotics (these two types of antibiotics aren’t effective any more).

That process can repeat for who knows how many cycles, which means that there will eventually be a bacteria strain that is immune to loads of types of antibiotics. This kind of strain is known as a superbug, and one example is MRSA.

Because MRSA is resistant to many antibiotics, it is relatively common, especially in hospitals, and could be fatal.

However, although MRSA is common, the chances of such strains mutating into superbug are extremely low, and those that do develop resistance normally only have partial resistance. So by following the prescribed medication cycle, the antibiotic still has a better chance at destroying these mutating strains before they become too powerful.

But the problem is because we use so much antibiotics, resistance strains are bound to arise.

One of the contributing factors to this problem is with the doctors. Many of the antibiotics prescribed to treat an individual are actually unnecessary. For example, prescribing antibiotics to viral infections (which the antibiotics can’t treat), or prescribing antibiotics to patients whose illness isn’t really severe.

However, the most important factor has to be farming. On many farms, farmers give the animals antibiotics regularly in their food, to prevent them from developing illnesses in the first place. However, this means that these farms have become a breeding ground for antibiotic-resistant bacteria strains that may potentially become superbugs.